1. Field of the Invention
The present invention relates generally to forming threads on the internal surface of a sleeve and, more particularly, to a method and apparatus amenable for use in on-line production process for forming threads on the internal surface of a deformable sleeve.
2. Description of Related Art
In the manufacturing of a great variety of small parts, a sheet or strip of metal is acted upon by a set of progressive dies which successively apply a forming operation to the metal one step of which typically includes threading one or more sleeves. The standard technique for such thread production has consisted of moving the workpiece into a threading station where an appropriately dimensioned tap is threaded in a forward direction into the sleeve to produce threads on the sleeve and then rotated in reverse direction to remove it from the threaded sleeve. The disadvantages of such a process are, first of all, the requirement for switching the direction of rotation of the tap requires additional apparatus and the time involved in removing the tap is, of course, not usefully applied. Secondly, the tap after being driven forward to produce the thread is then subjected to a redundant operation of merely removing the tap from the threaded sleeve which increases the frictional wear on the tap decreasing its useful life.
It is therefore a desideratum to provide apparatus and a method for producing threaded sleeves in a production process which is capable of effecting high volume production and reducing the disadvantages and unnecessary costs of present day known threading techniques.